Method for de-rinding and trimming a piece of meat or a piece of slautered animal

ABSTRACT

A device and a method are proposed for de-rinding or trimming a piece of meat or piece of a slaughtered animal, in which an arrangement device for the arrangement of the piece, an industrial robot with a manipulator arm and a sensor system, which detects the part that is to be separated, are provided. The sensor system comprises a camera and an image processing system as well as, if necessary, a distance measuring system, which determines the distance between a predefined zero point and a measuring point on the surface of the piece. Further, a cutting tool is provided, which separates the part from the piece.

STATE OF THE ART

The invention relates to a device and a method for de-rinding ortrimming a piece of meat or a piece of a slaughtered animal inaccordance with the generic term of Claim I

In the processing of a piece of meat or a piece of a slaughtered animalskin, fat, muscles, tendons and rind are removed. If the piece of meathas a relatively uniform thickness, the de-rinding and skinning can takeplace by means of a machine with the help of a skinning, fleecing and/orde-rinding device. For example, this holds true for a boned belly ofpork. The remnants of fat which are left over in the automaticprocessing of a meat plate or the remnants of meat which are left overin the automatic processing of a plate have up to now been removed byhand. The processor must distinguish between muscle meat and fat. At theedges of the boned belly of pork there are frequently skin foldspresent. Due to the irregular thickness a post-processing by hand isalso necessary at these places. This processing by hand is not only timeconsuming and costly, but rather is also connected with a danger ofinjury for the processor.

The rinding of a boned pork has up to this point also occurred partiallyby hand. The ham with the foot or the shoulder with the ribs is removedby a processor by hand and guided to the blade of a rinding machine. Inthe process the ham must be aligned in such a way that the blade cangrip the rind during the cutting. As soon as the blade has penetratedthe rind, the ham is pressed against and turned to the blade by means ofrollers. This represents a high risk of injury for the processor inparticular in the region of his hands. In addition processing by hand isconnected with high expenses.

THE INVENTION AND ITS ADVANTAGES

In contrast to this the device of the invention with the features ofClaim I has the advantage that the parts to be separated are detected bya sensor system. For this purpose a camera with an image processingsystem and perhaps additionally a distance measuring system areprovided. The camera and the image processing system record thecoordinates of the part to be separated in particular at its surface intwo or three dimensions. The distance between the surface and the manualmanipulator arm of the robot can be recorded with the image processingsystem or with a distance measuring system. Therewith the coordinates ofthe surface of the part to be separated can be completely recorded.These recorded data are processed by microprocessors into signals. Thesignals steer either a cutting tool or a gripper on a manual manipulatorarm of an industrial robot. The manipulator arm guides the cutting toolto the piece, which is either resting or moving at a constant speed.With the help of the cutting tool the parts are separated from thepiece. The manual manipulator arm equipped with a gripper receives thepiece and guides it to a stationary cutting tool. In the process thegripper aligns the piece in such a way that the part can be separated bythe cutting tool.

A post-processing by hand is not necessary. To make absolute certainthat the parts have been completely separated, the piece can be examinedagain after processing with the help of the camera and the imageprocessing system. If there are still remnants on the piece, the cuttingtool is activated again. The control of the manual manipulator arm takesplace with the help of a computer.

Using the device of the invention areas of meat pieces or pieces ofslaughtered animals can be processed which are irregularly formed oronly accessible with difficulty and which thus up to now could only beprocessed by hand. The camera and the image processor are used todistinguish between the parts to be separated and the surroundings.

The foodstuff pieces processed with the device of the invention canundergo further processing or packaging after separation of theundesirable pieces.

The industrial robot can either be a robot with a manipulator arm withseveral degrees of freedom or it can be a Scara robot with a manipulatorarm. In the case of the latter robot, the number of degrees of freedomis lower, but is sufficient depending on the application.

One advantageous design of the invention provides a sender, a receiverand an evaluation unit. The determination of the distance takes place ina non-contact manner. In the process the sender and receiver can useoptical or acoustical signals. For example, a laser range finder can beused. If the surface of the piece to be processed is nearly level, it issufficient to determine the distance between a zero point and ameasuring point at the surface of the piece in the range of the part tobe separated. This holds true for example with a boned belly of pork.The manipulator arm with the cutting tool is then moved a distance awhich is determined from the measured distance, at the surface of thepiece. Finally the cutting tool is moved in an area above the surface ofthe piece, which corresponds to the part that is to be separateddetermined with the help of the camera and the image processing system.In the process the cutting tool is driven in such a way that the part iscut off from the piece. The parts that are to be separated can beremnants of meat or fat, which remain on the surface during themechanical de-rinding. Such remnants have, up to now, been removed byhand with the help of a trimmer. Such trimmers are knives with acircular rotating blade with a cutting depth setting. Such a knife canbe provided on the manipulator arm for the removal of remnants. Sincethe red muscle meat and the white fat differ from each othersufficiently in color, the areas can be differentiated from each otherwith the help of the camera and the image processing system. Thethickness of the area can be determined at least approximately from thesize of the areas to be separated. The cutting depth is adjusted inaccordance with the thickness. The manipulator arm equipped with atrimmer moves along the surface and separates the remnants from thepiece.

A disk-shaped rotating blade can also be used in place of a trimmer witha circular blade. In addition, other knives which perform obliqueshearing or which are operated at a sawing motion are possible.

A further advantageous design of the invention provides three sendersand one receiver, in order to determine the distance between threemeasuring points and one prescribed zero point. If the surface of thepiece is not level, as for example is the case with the outward pointingsurface of a slaughtered animal half, it is not sufficient to determinethe distance between the surface and a zero point. It is necessary todetermine the shape of the piece at the area that is to be processed.This takes place by means of determining the distance between threemeasuring points and one zero point. In the process, the three measuringpoints must not be located on a line. The rise and fall in the examinedarea can be determined from these data. This results in not only thedistance which the cutting tool must travel to the surface of the piecebut also in the angle under which the cutting tool must be applied atthe surface. Such processing is, for example, necessary for de-rindingalong the cutting lines of a half of a slaughtered pig. Along thecutting lines the slaughtered animal is divided into several largerpieces. Up to now the belly of pork is not flayed until after theremoval of the bones. However, this has the disadvantage that the edgesof the belly of pork exhibit skin folds and therefore cannot becompletely de-rinded/flayed by machine. There are always skin remnantson the edges. Using the invention's device the pork halves can be flayedalong the cutting lines prior to further cutting and removal of thebones of the belly of pork. The cutting lines that delimit the belly ofpork, where skin folds occur, are located at the shoulder and above thehind leg. In order to flay in these regions, the suspended half of theslaughtered animal is attached to a plate with the help of clips. Theplate is of a color that differs greatly from the color of the pork, forexample blue. With the help of the camera and the image processingsystem the regions that are to be processed are detected using theoutlines of the pork half. Using the data from the range measurement thecutting tool, a de-rinding device, is guided to the surface and attachedunder the determined angle at the surface. In guiding the de-rindingdevice above the surface of the slaughtered animal the angle is, ifnecessary, to be varied corresponding to the shape of the surface.

The shape of the surface can also be determined with a camera and animage processor instead of using a distance measuring system.

The de-rinding and skinning device can be a mobile device, as used toflay by hand. In addition it is possible to use a stationary de-rindingand skinning device, which is guided to the piece with the help of agripper. This is not appropriate in the case of a slaughtered animalhalf, however stationary de-rinding devices are suitable for bellypieces, hams or shoulders that have already been boned. The skinning andde-rinding devices are based on the principle that above a drawingroller a processing material is pressed against a blade and moved towardthe blade. In the process, the part of the processing material locatedbetween the blade and the drawing roller is cut off. The thickness ofthe layer that has been cut off can be predefined by the distancebetween the drawing roller and the blade. Depending on the thickness andtype of layer that has been cut off, one speaks of de-rinding, skinningor fleecing.

To de-rind a ham with feet or a shoulder with ribs the piece is alignedon a base support in a predefined position. Using the camera and theimage processing system the rind and the position where the blade of ade-rinding device can be attached, are determined. Then a gripperarranged on the manipulator arm of the industrial robot grips the pieceand feeds it to a stationary de-rinding device. As soon as the blade ofthe de-rinding device has penetrated the rind, the piece is transportedwith the help of the drawing roller. The gripper can therefore disengagefrom the piece and does not pick it up again until the de-rinding hasbeen completed.

A further advantageous design of the invention provides a conveyor beltas an arrangement device. It serves the purpose of transporting thepiece from one processing station to the next. The piece lying on theconveyor belt can be analyzed by the sensor system, which is locatedabove. For this purpose the transport can be paused. The manipulator armof the industrial robot holds or processes the piece. If the pieceremains on the conveyor belt during the processing, it can be furthertransported on the conveyor belt after conclusion of the processing.

A further advantageous design of the invention provides a suctiondevice, which suctions the parts that have been cut off. The parts cansubsequently be collected and if necessary processed.

In accordance with a further advantageous design of the invention theindustrial robot is equipped with a cleaning device. For example, thecleaning device can be a steam cleaning device with a spray lance.Therewith the device can itself perform a cleaning of its parts thatcome into contact with the foodstuff pieces as well as the surroundings.

Further advantages and advantageous designs in the invention can beinferred from the claims.

All features of the invention can be essential to the invention bothindividually as well as in random combination with one another.

1. Device for cutting one or more parts of a meat piece or a piece ofslaughtered animal, characterized by the fact, that and arrangementdevice for the piece is provided, that an industrial robot with amanipulator arm is provided, that a sensor system is provided, whichdetects the coordinates of the part that is to be separated determiningthe surface of the piece, whereby the sensor system comprises a cameraand an image processing system, and that a cutting tool is provided,which separates the part from the piece:
 2. Device according to claim 1,characterized by the fad that the sensor system comprises a distancemeasuring system, which determines the distance between a predefinedzero point and a measuring point on the surface of the piece.
 3. Deviceaccording to claim 2, characterized by the fact that a sender, areceiver and an evaluation unit are provided as distance measuringsystem.
 4. Device according to claim 2, characterized by the fact thatthe distance measuring system is equipped with three senders andreceivers for determination in a non-contact manner of the distancebetween a zero point and three measuring points on the surface of thepiece.
 5. Device according to claim 3, characterized by the fact thatoptical or acoustical senders and receivers are provided.
 6. Deviceaccording to claim 1, characterized by the fact that a skinning and/orde-rinding device is provided as the cutting tool.
 7. Device accordingto claim 1, characterized by the fact that the cutting tool is providedon the manipulator arm.
 8. Device according to claim 7, characterized bythe fact that a knife is provided as a cutting tool.
 9. Device accordingto claim 8, characterized by the fact that the knife exhibits a circularor disk-shaped rotating blade.
 10. Device according to claim 1,characterized by the fact that a conveyor belt is provided as anarrangement device.
 11. Device according to claim 1, characterized bythe fact that a plate and several clips for attachment of the piece tothe plate are provided as an arrangement device.
 12. Device according toclaim 11, characterized by the fact that the plate exhibits a colordeviating from the color of the pieces.
 13. Device according to claim 6,characterized by the fact that a gripper is provided on the industrialrobot, which picks up the piece from the conveyor belt and feeds thepiece to a stationary skinning and/or de-rinding device.
 14. Deviceaccording to claim 1, characterized by the fact that a suction device isprovided for the purpose of suctioning the separated parts.
 15. Methodfor de-rinding or trimming a piece of meat or a piece of slaughteredanimal in particular with the help of a device according to one ofclaims 1, characterized by the following procedure steps: that the pieceis arranged or suspended and fixed on a base support, that the part tobe separated during de-rinding or trimming is determined in two or threedimensions with the help of a camera and an image processing systemand/or with a distance measuring system, that a cutting tool is guidedto the surface of the piece with the help of a manipulator are of anindustrial robot in correspondence to the determined data, that thecutting tool is moved along the surface in the area of the part to beseparated.
 16. Method according to claim 15, characterized by the factthat the distance between a predefined zero point and a measuring pinton the surface of the pieces is determined.
 17. Method for de-rinding apiece of meat in particular with the help of a device according to oneof claims 1, characterized by the following procedure steps: that thepiece is arranged on a base support,